The city has a prospective developer lined up for the old Joliet prison on Collins Street.

Mayor Thomas Giarrante described the potential deal as “preliminary.” But he was confident enough in the prospect to announce it during his State of the City address Wednesday.

“The Collins Street prison continues to be a challenge,” Giarrante told the audience.

Then, he added, “We have someone who is very interested in that prison. He has some great ideas. But first we need the state of Illiois to turn that propery over to us so we can work with that person.”

Giarrante would not elaborate on the prospective development later when asked for details. But the city would have to have some confidence in the prospect if it is willing to take over the aging prison from the state of Illinois.

The former Joliet Correctional Center has deteriorated to the point that a consultant hired by the city last year reported that if the prison is not renovated in the near future it would become irreparable.

The prison was built in 1858. Its limestone walls and guard towers give it an iconic look that has been used for settings in movies and TV shows. The city set up a visitors’ site in the parking lot with sign boards telling the history of the prison to accommodate travelers who stop to see the prison during trips through Joliet.

But the state shut down operations in 2002, and there has been little upkeep since.

The city has looked for prospective developers who might be interested in turning the prison into a tourist destination, something that has been done with other prisons with historical value.